Sheet metal screw socket



Sept. 20, 1938. A. B. RYPINSKI SHEET METAL SCREW SOCKET Filed NOV. 24, 1936 Q YIIIIIIIIIII/IIIIII I w M Ma m 1 Patents-4:1 Sept. 20, 1938 Qumran STATES PATENT OFFICE SHEET METAL SCREW SOCKET tion of New York Application November 24, 1936, Serial No. 112,497

2 wishes.

The invention herein disclosed relates to an article made from sheet metal and in particular to the construction of a tapped socket for receiving a machine screw.

Heretofore, in the construction of sheet metal articles, it has been the practice wherever it was necessary to secure two angularly disposed memhere or sections together by a machine screw, to provide an angular-1y disposed lug or an angle secured to one of the members. "ll'his lug or angle is drilled and tapped to receive the machine screw. For example, in the construction oi sheet metal cabinets, and particularly electrical conduit boxes and switch cabinets, it is the common practice to secure several lugs to the side walls, or provide the equivalent thereof by cutting a tongue in the metal which is bent at right angles to the side wall. .These lugs are drilled and tapped to receive machine screws that pass. through openings in the cover or an intermediate partition, as the case may be, that is to be secured to the side wall.

By this invention, the necessity for these lugs is eliminated. In accordance with the invention there is provided a screw-receiving socket that is formed out of the sheet metal. The sheet metal is lanced and the strap formed by lancing the metal isdrawn and shaped to forms. semicylindrlcal strap. In addition the sheet metal on L either side of the strap is pressed to form a semicylindrical groove which with the semi-cylindrical section of the strap forms a socket, the ems of which is parallel to the plane of the sheet metal piece, or it may be inclined thereto. When the socket is tapped it provides a satisfactory socket for a machine screw with suiliclent threads of suflicient depth to retain a machine under all ordinary forces exerted by tightening a machine screw.

Two cabinets having such threaded sockets are illustrated in the accompanying drawing in which:

Fig. -l is a. section through a sheet metal box or cabinet for an electrical conduit system, the cover being secured on the box by machine screws;

Fig. 2 is an enlarged, fragmentary section taken on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged, transverse, fragmentary section taken on the line 3-8 of Fig. 2;

Fig. 4 is a fragmentary, side elevation of a. corner of another box, one in which one side wall is secured to the adjacent side wall by a machine screw;

Fig. 5 is a fragmentary. plan view of the some, looking into the open end of the box; and

- cutting threads of the tap bite into the metal of Fig. 6 is an elevation of a tap used in threading the machine screw socket.

In Figs. 1 to.3 there is illustrated a sheet metal box 6 with the side walls and bottom stamped from a single piece of sheet metal, the sides being 5 welded together. A cover 2 having lateral depending fianges 2a which overhang the sides of the box is provided for the box. The cover 2 is secured on the box by means of machine screws 3, one of which is illustrated enlarged in Figs. 2 and 3. 3 I

Threaded sockets are provided in the side walls of the box to receive the machine screws 3. Each of these threaded sockets is formed out of the material of the side wall in the manner illustrated 15 in Figs. 2 and 3. The socket shown in these figures of the drawing is formed by drawing a portion of the metal'of the side wall, adjacent the. edge, to form an inwardly extending offset portion or bulge d. This onset portion is lanced to a form a strap 5 united to the odset portion at each end but disconnected along its side edge. The metal of the strap 5 is drawn to form a section 51; of substantially semi-cylindrical configuration extending into the box, the axis of the semi-cylin- 25 drical section 5a being parallel to the plane of the side wall and perpendicular to the plane of the cover. A semi-cylindrical depression ii, coaxial with the semi-cylindrical section 5a of the strap, is formed in the ofiset portion 6 of the side wall. These two semi-cylindrical sections form in effect a cylindrical socket.

In threading this socket to receive a. machine screw, a tap I such as illustrated in Fig. 6 is used. This tap has along section la between its end 35 and the beginning of the eflective threads. The section To is of sumcient length to pass through the strap 5 and engage the inner end of the oilset portion 4 of the side well before the eii'ectlve the strap. If an ordinary tap is used, it has a tendency to pass through the slot formed by lancing the ofiset portion 4 as it is opposed by the strap 5 on one side and has no resistance on the other. when however the end of the tap extends below the strap i it is held by the offset portion 4 coaxially wlththe axis of the section to of the strap and the depression 8 in the offset portion I.

The machine screw I extends through an open-. log in the cover that is aligned with the socket formed in the side wall. The threads of the screw engage the threads cut in the strap 5 and the threads cut in the wall of the depression 6 in the onset portion 4. While the walls of the socket are not continuous, nevertheless there are suiiiclent threads engaging the threads of the screw 3 so that the force exerted by tightening the screw 3 in the ordinary manner, that is,

' with a hand screw-driver, is resisted and the contact of the threads is sufllcient toprevent a stripping oi the threads.

The oii'setting of the portion .4 servestwo pure poses. It relieves thetap from cutting except where it is desirable to cut threads and it moves the screw head in from In the; box illustrated, countersunk finishing washers 8 surrounding the screw 3 are used,- but these form no part of the invention. i

' In Figs. 4 and 5 a corner of a box 9 is 'a single piece of sheet metal but All of box. In the side wall I H there is formed a threaded socket denoted generally by through an opening the numeral II. This socket is in all respects similar to the socket formed in the box I illustrated in-Figs. 1 to 3, except that the axis of the socket I2 is perpendicularto the plane of the side wall iii. A machine screw it extends coaxial with the socket i2 and engages the threads ofthe socket l2. The wall III is shown slightly spaced from the edge of the wall II for the purpose of illustration. but when the screw II is tightened the wall ii! is firmly clamped against '.theedgeofthewallll. It will beapparent to those skilled in the" art that by the construction illustrated in the draw- F ing anddescribed above, there is provided a convenient and effective machine screw socket for v and. inexpensively the edge of the coven illustrated. This box has the bottomand'side walls formed from the upper ends of adjacent-side walls of the box I are securedjo'gether by machine screws. "the sidewalls are similarly secured together in the 'n'iariner'of the side walls iii and II forming the illustrated corner of the pressed to" formin, the side wall .iil that is.

sheet construction s. The-socket is readily form an obstruction,-

While the invention socket for a machine screw it will be a t that it is equally useful with other fasteners such for example --as x .a .stud, bolt. -It is .-.also. obvious that various changes may be made by 'those' skilled in the art in the details oi the specific embodiments illustrated in the-.drawing and described in detail a'bove within the principle and scope of the invention as expressed lclaimz' 1. In a sheet metal cabinet construction having walls oi sheet metaL-the feature of novelty consisting of a wall of the cabinet having a portion an arcuate in the appended claims.

has been I II I;

depression, spaced."

formed and does not in the manner of ailu'g extend from the side wall to parallelsiits traversing the arcuate depression and the space between the slits struck out forming an arcuate strap extending from" the mace o! the wall-and forming with the 'arcuate depression a substantially cylindrical socket, the inner'surface of the strap and thearcuate depression on each side'ot the strap being threaded to receive a machine screw.

2.In a sheet metal ing walls of sheet metal,

cabinet construction hav-- the ieature of novelty consisting of a wall of the cabinet having a porwall, spaced, parallel slits. 

